Cut-back-die-thread machine.



. I r a. 4 I ...-.w v 'vrn UNITED STATES PATENT OFFICE. EDWARD E. BECK, or CHICAGO, ILLINOIS, AssIeNoa ro caown nm a TOOL comramr,

or CHICAGO, ILLINOIS, A ooarorearroiv or L'LmoIs.

CUT-BACK-DIE-THREAD macnnm.

'milling or cutting back die teeth in order that when in operation they may freel y discharge their cuttings, an operation which is not only obj ectionably expensive, but obviously inaccurate as compared with that possible and practical by means of a machine uniformly as must be cutting back th tooth in adie.

The object of my inventionfbroadly stated, is a construction and arrangement of devices which may be mounted upon the bed plate of any ordinary and commonly used drill press which will serve to hold and present to a mechanically revolved cutter a die, the teeth of which must be milled or cut back prior to its use and in such a manner as to insure a rapid and uniform cutting back of the teeth in every operatingcutter tooth ofsuch a die.

More specifically stated, the object of my invention is a device in which the teeth of a cutting die may be used as a means for se curing the die in its operative position rela tive to a milling cutter, revolved about a fixed axis, and in such a manner that the several cutters of the die maybe shifted to operative engagement alternately with a revolving cutter, and locked against possible accidental movement-during the milling of the die teeth. Y

A further object of my invention is-a die thread cut-back machine, simple, cheapand durable in construction, convenient of access and operation, and within the perfect control of a single operator, and; to andfrom which the dies may be secured and removed.

With these ends in view, my; invention finds embodiment in certain features of TIOV'. elty in the construct-ion,Ecoinbitiation and arrangement of parts by which the said objects and certain other objects are hereim after attained, all as fully described with reference to the accompanying drawings, and more particularly pointed out inthe claims.

Specification of Letters Patent.

Application filed December 1, 1911 Serial No. scams.

PatentedApr. 15,1913;

In said drawing: Figure 1 illustrates in top plan view a die thread cut-back machine 1n which my invention finds embodiment; with the revolving cutter or milling device shown in cross section. Fig. 2 is a transverse section on the irregular line 22 'of Fig. 1. Fig. 3 is an enlarged detail plan;

view of the die to be cut, with dotted lines showing 'the adjustment of the revolving-- cut back device in its operative position against one of the cutters and away from .another cutter of the cutting die, and Fig. 4 is an enlarged detail plan view illustrating the operative position of the revolving cutter wit-h reference to a cuttingzdie tooth when milling or cut-ting such tooth back.

Similar characters of reference. indicate 7 the same parts in the severalfigures of the drawing. I

5 indicates the bed plate of a drill press upon which is mounted and secured in any. suitable manner a base plate 6 in a suitable. recess in WhlCh is a sliding block 7 receiving the screw threaded ends 8, 8 of bolts 9, 9 projected through a head block 10. The head block 10 is provided with a central opening into and through which is screwed the shank 11 of a screw threaded die holder 12, the head block'being supported upon a I rod 13 seated and free to turn in a circular groove 14, extending longitudinally of the sllding block 7 the head block 10 being also provided with a circular groove 15 in which the rod 13 seats. j

The head block 10 is cut away at its opposite ends 16 as shown in full lines in Fig. 1 and indicated by a dotted line in Fig. 2, for seating the heads of the bolts in a plane below the upper surface of the head block and for convenience of manipulation, for adjustin the head block, but the resting of the hea block as itdoes upon the rod 13,

not only substantially relieves the bolts 9 from the weight of the head block, but pro 'vides .for conveniently and easily tipping the head block when adjusting it to the desired plane by-means of the screw bolts 9. 9.

The shank 11,. byflmeans of its screw threadedend is adjustable toward and from the sliding block 7 so that by screwing-the die holder down-or up in the head block, it may be raised and lowered with reference to the milling cutter, that is to say vertically adjusted, the shank 11 being locked in its adjusted position by means of a screw bolt 17 actuatednby a rod 18 passing through a head 19 at its outer end, the inner end of the screw 17 having a bearing laterally against the shank 11.

The holder 12 is more or less cone shaped tion below a milling cutter 21, the upper end of the shank 22 of which is screwed into the head 23-of a rotating shaft of a drill press only a part of which is shown in ,the drawing,' a bracket 24: projecting from the standard 25 serving to guide and steady the rotating shaft.

In order to shift the several cutters of the die plate to cutting engagement with the milling cutter 21 (see Fig. 1) a lever 26 is pivoted to the base plate 6 by means of a screw 27 which lever projects through a swivel 28 on the sliding block 7, and projects forwardly in reach of the operator, the die plate being locked by means of, a locking lever 29, pivoted to a lug 30 on the end 16 of the head block'lO. w

The inner portion ofthe locking lever 29 works in a depression or slot in the head block 10, and at its extreme inner end is provided with an upwardly projecting lug 32, which. when elevated to its locking position engages the adjacent side wall of cutter of the die being operated upon by the press die cutter, 21, as clearly shown in Fig. 1, and from which engagement with it the lug 32 is released by lifting the outer end of the lever 29, and by releasing the die holder from its engagement with the screw bolt 17 and then taking hold of the die plate and turning it to a position engaging the locking lug 32, which in the meantime has been elevated to its operative position. In other words, with the die plate 33 screwed to its operative position on the die plate holder 12, as shown in Fig. 1, the lug 32 is lifted to engagement with the cutter 34,-the die holder being then locked by screwing up the bolt 17 to engagement with its shank, and then following the completion ofthe cutting back of the teeth in cutter 34, the screw bolt is loosened, the lug 32 depressed, andthe die turned until the cutter 35 is swung to engagement with the lug 32, which in the meantime has been elevated forthat purpose, and whereupon the screw bolt 17 is again tightened and so on with the cutters 36 and 37. of the dieplate.

In operation the die plate is first screwed quite tight upon the holder 12, when the outer end of the lever 29 is depressed until a die' cutter engages the lug 32, whereupon the die plate is locked against turning'by the screw 17, and the cutter then moved to operativeengagement with the die press cutter the 7 21 by the operator shifting the sliding block 7 through the medium of the lever 26, and by means of which he has under perfect control the cutting force of the milling cutter. The lever 29 with its lug 32, not only operates as a stop limiting the die cutter to be operated upon, but also as a gage fixing the point at which the cutters must be held for cutting back the teeth of the die plate at the point they should and must be, and along the proper curve or angle without injuring the cutting end or edge of the teeth, for it will be observed that in practically all cutting dies, the cutters for obtaining the best effect in operation, and especially when there are four, are arranged on lines radial to the axis of the die and at right angle to the adjacent cutter.

It should now be observed that but one cutter of the die can at any time be brought to contact with the milling cutter 21, and that the position of the cutter when operating upon a die chaser is such that the-milling'cutter is tangential to the circle of the base of the die teeth and on a line outwardly beyond the die cutter. In other words the cutting action of the milling cutter into the chaser is on a curved line which is tangential to the curvature of the die teeth, and the teeth of the milling cutter therefore cut back without cutting into or substantially cut-ting into the curved base between the cutting points of the die teeth, that is to say, the shanks of the chaser teeth are cut back without cutting into the cutting point of their teeth.

The enlarged plan view in Fig. '3 illustrates in plan view the relative position of the milling cutter to the teeth of the chaser 34 while being cut back, while the enlarged detail in Fig. 4 shows a plan View of one of the teeth after it is cut back, with dotted lines showing the positions of the curved base of the tooth before it is cut back by the chaser cutter. When the teeth of the cutting die in contact with the milling cutter have been sufiiciently cut back, the remaining uncut teeth which have been used for securing the-cutting die to the holder and therefore not cut back, are, planed down or cut oflf.

In conclusion it should be observed that the embodiment of my invention is not limited by the details of construction shown, as for example the means by which the die cutter is shifted and locked in its several operative posit-ions, for obviously other means might be employed serving the same purpose, which as such might be mechanically substantially diiferent from those herein described'and in some instances it might be possible and practical to have the die cutter held in a 'fixed position and to shift the chaser cutter to t e several positions necessary for cutting back the teeth of the die.

- justed, a sliding Having described my invention what I claim and desire to secure by Letters Patent 1s prising in combination a holder for the die, a milling cutter above said holder,'1neans for actuating said cutter, and means for adjusting the several cutters of a die thereto.

2. A die. thread cut-back machine comprising'in combination a die support, a revolving milling cutter in a plane above said support, and means for shifting the support to bring the several cutters'ofthe die successively in operative contact with each set of teeth in the milling cutter, substantially as described.

3. A die thread cut-back machine comprising in combination a milling cutter, a die support in a plane below said cutter, an adjustable rocking head block for the support, and means whereby said support and head block may be adjusted with reference to the milling cutter and the head block and support may be rocked in adjusting them to the cutter, substantially as described.

4. A die thread cut-back machine comprising in combination a die support, a rocking head block in which said support is adblock supporting said headblock, a rotatable milling cutter wholly above the holder, and *means for adjusting the head block substantially as described.

5. A diethread cut-back machine comprising in combination a base plate, a sliding block mounted thereon, a head block supported above, and means for-adjusting and rocking said head block, a die support rotatable in the head block, and means for locking said support against turning, substantially as described. Y

6. A die thread cut-back machine comprising in combination a sliding block, a. head block, a diesupport screw-threaded in and projecting through said head block, a

rod interposed between the sliding block and the cutting die support upon which the head i block may be oscillated, and means at op- 1. A die thread cut-back machine comthrough said head block,

posite sides of said rod by which the cutting die support is both vertically and laterally rocked and vertically adjusted, substantially as described.

7 A die thread cut-back machine comprising in combination abase plate, means for securing said plate to the bed plate of a milling cutter, a sliding block seated in the base plate, a head block, and an adjustable die support, the shank of which projects meansfor adjustably rocking said support, and means for locking said support and the head block against movement with reference to the sliding block when adjusted, substantially as described.

8. A die thread cut-back machine comprising in combination a die, means for tightening said die on its support, means for rotating said support, a pivoted lever provided with a lug adapted to engage the die and limit the rotation of the support, means for locking said support against rotation, and means for laterally rocking and adjusting the support, substantially as described.

9. A die thread cut-back machine comprising in combination a sliding block, a

head block supported above, and adjustable with reference thereto, a die support, the shank of which projects through 'the head block, a roller interposed between the support and the sliding block, said support being provided with threads adapted to mesh with the threads of the die and tighten the same thereon, a milling cutter revolving upon a fixed axis and means ior adjusting the teeth of the die to contact with the milling cutter for die, substantially as described.

In witness whereof, I have hereunto set my hand and afiixed my seal, this 20th day of November, A. D. 1911.

' j EDWARD E. BECK. [n s.] Witnesses: I

Jno. G. Enn'rorr, Mmmnn ELSNER.

cutting backthe teeth of the- 

